Objective: To compare the efficacy and safety of tranexamic acid and norethisterone in the treatment of ovulatory menorrhagia.
Design: A randomised, double-blind, placebo controlled study.
Setting: University Department of Obstetrics and Gynaecology, Addenbrooke's Hospital, Cambridge.
Subjects: One hundred and three women complaining of heavy periods with a regular cycle recruited directly from general practitioners within the hospital catchment area and from consultants' gynaecology clinics.
Interventions: There were forty-six women on placebo with confirmed ovulatory menorrhagia, defined as menstrual blood loss greater than 80 ml/cycle and mid-luteal serum progesterone concentration greater than 9 nmol/l). Twenty-one received norethisterone (5 mg twice a day on days 19 and 26) and 25 received tranexamic acid (1 g four times daily on days 1 to 4) for two cycles.
Main outcome measures: Menstrual blood loss was measured using the alkaline haematin method. Haematological assessments were made both at the beginning and at the end of the study, questionnaires were given to assess subjective endpoints, and patients were asked to report any adverse events during all cycles.
Results: Tranexamic acid reduced mean menstrual blood loss by 45%, from 175 ml to 97 ml (95% CI for the difference in menstrual blood loss 52 to 108, P < 0.0001), norethisterone increased mean blood loss by 20% from 173 ml to 208 ml (95% CI for the difference in menstrual blood loss -64 to 2, P = 0.26). Fourteen (56%) women who received tranexamic acid achieved a mean menstrual loss of less than 80 ml per cycle during treatment, but only two (9.5%) who received norethisterone achieved this mean menstrual loss. There were no serious adverse events reported for either drug.
Conclusions: Tranexamic acid is a safe and effective form of medical therapy in women with menorrhagia and is highly likely to normalise blood loss in women losing 80 to 200 ml prior to treatment. Norethisterone at this dose is not effective therapy for ovulatory menorrhagia.